Thomas j



(N0 Model.)

T. J. HOUCK.

BUSHING FOE ELBGTRIG ARC LAMPS. No. 523,893. Patented July 31, 1894.

W idling! n '5, IIIII l lNVENTOH WITNESSES:

wwfl i ATTORNEYS.

UNITE STATES PATENT OFFICE.

THOMAS J. HOUCK, OF BALTIMORE, MARYLAND, ASSIGNOR OF ONE-HALF TO JAMESFRANK MORRISON, OF SAME PLACE. 4

BUSHING FOR ELECTRIC-ARC LAMPS.

SPECIFICATION forming part of Letters Patent No. 523,893, dated July 31,1894.

Application filed April 23, 1894.

' which holds the upper carbon passes through two guides which soonbecome worn in consequence of the friction of the holder through thesame, due to the continued motion of the holder in automaticallyadjusting the arc and feeding the carbon down as it is consumed. Whenthese guides for the carbon holder become worn, so that they are toolarge, the carbon holder is liable to assume positions which are out oftrue vertical alignment with the lower carbon, and sometimes the carbonwill become jammed in this false position and remain stationary, so thatthe distance between the carbons soon becomes so great from the burningaway of the carbon without feeding down, as to permit the arc to bedestroyed and the light to go out. This involves great inconvenience tothe community and corporation, and danger to the lineman whose duty itis to fix it while the current is on.

My invention is designed to provide a detachable and adjustable bushingfor these carbon holder guides which may be tightened or adjusted fromtime to time to take up wear and always hold the upper carbon holder andits carbon in true vertical alignment, and at the same time to avoid thenecessity and expense of throwing away the old guides and replacing themwith new ones.

To these ends my invention consists in the peculiar construction andarrangement of the bushings for the said carbon holder guides, and theircombination with the adjoining parts, which I will now proceed todescribe with reference to the drawings, in which-= Figure 1 is a frontview of a part of an ordinary Thomson-Houston lamp with the carbonholder guides in section, and showing my invention applied thereto. Fig.2 is a cross section through the line 2=2 of Fig. 1. Fig.

3 is an enlarged side view of my bushing partly shown in section, andFig. t is a top or plan view of the same.

A is the upper and B the lower carbon of Serial No. 508,675. (Nb model.)

an ordinary arc lamp. lhe upper carbon is held in a tubular holder 0 bymeans of a set screw a and this tubular holder moves vertically throughguide plates D and D. It is the bushings for these guides whichconstitute my invention. As the bushings for both these guides aresubstantially alike it will be sufficient to describe one of them.

Referring to Figs. 3 and 4, E is the bushing, which consists of a metalsleeve provided on its exterior with a tapered screw thread, and has acentral hole large enough to permit the carbon holder to freely passthrough the same. At the larger end the bushingis slitted longitudinallyat b, and at its edge it has a thickened rim 0 carrying a series ofradial spring seated stems 6 having upon their inner ends plates (1which bear against and form an electrical contact with the carbonholder. Where these stems e pass through the rim 0 the latter ischambered out to receive a spiral springf, one end of which bearsagainst the bushing and the other against the plate d. This stem at itsouter end is screw threaded and carries an adjusting nut g which may beturned to regulate the position of the plate 61 and the tension of thespringf. This spring serves to hold the plate at against the carbonholder with a constant pressure, while the nut g allows the plate d tobe drawn away from or advanced to the carbon holder to compensate forvariations in size or looseness that comes from wear.

The bushing E is screwed into an internal screw thread of the guideplates D and D, and its tapering form in connection with the slits bgive it also another adjustment to take up looseness or wear, for bysimply turning up the bushing more tightly its slits and the taper ofthe screw thread cause its larger end to be compressed like springtongues about the carbon holder, causing the plates d to bear moreclosely against the same. The expansive tendency of the large end of thebushing also causes the screw threads to bind against the screw threadsof the guides with a frictional contact which causes the bushing to holdor maintain its adjustment and prevent all looseness and accidentalturning of the bushing.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. An adjustable bushing for the carbon holder of electric arc lamps,having longitudinal slits forming spring tongues, and having upon itsexteriora tapering screw thread adapted to compress said spring tongueswhen screwed into a socket, substantially as described.

2. The combination with the carbon holder guide in an electric arc lamp;of aremovable bushing having an external tapering screw thread and slitsat the larger end of the same substantiallyas and for the purposedescribed.

3. The combination with the carbon holder guide in an electric arc lamp;of a detach- THOMAS J. HOUOK. Witnesses:

Enwn. W. BYRD, H. J. ROBINSON.

